Yue Changwu, Liu Ning, Liu Minghao, Lü Yuhong, Shao Meiyun, Wang Miao, Ai Guoming, Huang Ying
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, No. 1 West Beichen Road, Chaoyang District, Beijing, 100101, China,
World J Microbiol Biotechnol. 2015 Apr;31(4):541-8. doi: 10.1007/s11274-015-1825-2. Epub 2015 Feb 20.
The draft genome sequence of marine Streptomyces olivaceus strain FXJ 7.023 contains a cryptic Type III polyketide synthase (type III PKS) gene cluster, which is similar to the Streptomyces coelicolor THN biosynthesis gene cluster. A putative type III PKS (SoRppA) gene and its adjacent gene for cytochrome P450 158A2 (SoCYP158A2) of this gene cluster were cloned by PCR screening through a fosmid genomic library of S. olivaceus FXJ 7.023. Tandem expression of SoRppA and SoCYP158A2 in Escherichia coli strain BL21 (DE3) plysS resulted in obvious biosynthesis of phenol and indole, while heterologous expression of SoRppA or SoCYP158A2 alone did not. The engineered strain sorppAcyp158a2BL21 showed tolerance to phenol concentration up to 0.75 g/L. Continuous biosynthesis of phenol and indole by the immobilized engineered strain on macroporousresin was achieved, and the productivities of phenol and indole in extractant-free culture in 102 h were 0.08 and 1.525 g/L/h, respectively, with the highest production reached 0.67 and 14.48 g/L, respectively. These results suggest that the engineered strain and immobilized continuous fermentation process may provide potential for "green" production of phenol and indole.
海洋橄榄色链霉菌菌株FXJ 7.023的基因组序列草图包含一个隐秘的III型聚酮合酶（III型PKS）基因簇，该基因簇与天蓝色链霉菌THN生物合成基因簇相似。通过对橄榄色链霉菌FXJ 7.023的fosmid基因组文库进行PCR筛选，克隆了该基因簇的一个推定III型PKS（SoRppA）基因及其细胞色素P450 158A2（SoCYP158A2）的相邻基因。SoRppA和SoCYP158A2在大肠杆菌菌株BL21（DE3）plysS中的串联表达导致了苯酚和吲哚的明显生物合成，而单独异源表达SoRppA或SoCYP158A2则没有这种现象。工程菌株sorppAcyp158a2BL21对高达0.75 g/L的苯酚浓度具有耐受性。实现了固定化工程菌株在大孔树脂上连续生物合成苯酚和吲哚，在无萃取剂培养102 h中苯酚和吲哚的生产率分别为0.08和1.525 g/L/h，最高产量分别达到0.67和14.48 g/L。这些结果表明，该工程菌株和固定化连续发酵工艺可能为苯酚和吲哚的“绿色”生产提供潜力。
